Kentucky bluegrass plant named ‘B-5.0815’

ABSTRACT

A variety of Kentucky bluegrass produced vegetatively by rhizomes, tillers and apomictic caryopses, distinguished by a unique combination of characters including coarse leaf blade width and high dry matter yield under grazing.

Latin name of the genus and species of the plant claimed: The presentinvention relates to the genus and species Poa pratensis L.

Variety denomination: ‘B-5.0815’.

Field of invention: The present invention relates to a new and distinctasexually reproduced variety of perennial Poa pratensis L.

BACKGROUND OF THE INVENTION

This invention relates to a new and distinct perennial Poa pratensis L.cultivar identified as ‘B-5.0815’ Kentucky bluegrass (herein referred toas ‘B-5.0815’). The inventor, Virginia G. Lehman, discovered ‘B-5.0815’under cultivated conditions in a planting of Kentucky bluegrassseedlings near Lebanon, OR. ‘B-5.0815’ was identified as a distinctlydifferent vegetative segregated clonal plant differing by much highertiller density and forage production than the surrounding plants. Theinventor asexually reproduced ‘B-5.0815’ by taking vegetative cuttingsof the plant material from the plant including rhizomes and tillers,cutting the rhizomes into segments, each with a vegetative bud, androoting them in pots in a greenhouse near Lebanon, Oreg. Vegetativeplugs of ‘B-5.0815’ were asexually reproduced and moved to fieldnurseries of near Lebanon, OR for further evaluation.

For purposes of registration under the “International Convention for theProtection of New Varieties of Plants” (generally known by its Frenchacronym as the UPOV Convention) and noting Section 1612 of the Manual ofPlant Examining Procedure, it is proposed that the title of theinvention is Kentucky bluegrass plant named ‘B-5.0815’.

BRIEF DESCRIPTIONS OF THE ILLUSTRATIONS

FIG. 1 is a photograph of ‘B-5.0815’ Kentucky bluegrass plant in thereproductive phase in the field.

COMPLETE DESCRIPTION OF THE VARIETY

‘B-5.0815’ was characterized in greenhouse and field conditions.‘B-5.0815’ is a unique variety of Kentucky bluegrass (Poa pratensis L.)that was discovered under cultivated conditions in a field nursery ofKentucky bluegrasses planted from seed. ‘B-5.0815’ originated as an openpollinated progeny with ‘B-99.1435’ as the seed parent. ‘B-99.1435’ isan unpatented, unreleased, Kentucky bluegrass plant grown and maintainedin the plant nursery near Lebanon, Oreg., and whose parents are unknown.‘B-5.0815’ was identified as having a much higher leaf production thanthe surrounding Kentucky bluegrasses. The field nursery was located inUSDA Plant Hardiness Zone 8b. ‘B-5.0815’ was propagated by the inventorunder field and greenhouse conditions in Lebanon, Oreg. by cutting ofrhizomes and tillers, rooting them in soil, and planting of the rootedmaterial to provide planting stock for studying performance and forcomparison of morphological characters after propagation. ‘B-5.0815’ hasbeen propagated by stolons, tillers, and apomictic caryopses. Asexuallyreproduced plants of ‘B-5.0815’ from stolons, tillers, and apomicticcaryopses have remained stable and true to type indistinguishable fromthe mother plant through successive generations of propagation. Theapomixes level of ‘B-5.0815’ is approximately 90%.

‘B-5.0815’ is a perennial Kentucky bluegrass that spreads by rhizomes,tillers, and caryopses. Characteristics of ‘B-5.0815’ measured in 2008were taken from plants that were approximately 20 months in age grown ona Malabon Silty clay loam with pH of 6.8.

‘B-5.0815’ has a shorter plant height than ‘Kenblue’ (not patented) andis taller than ‘Baron’ (US Plant Variety Protection 7200117) (Table 1)when measured under field conditions in Lebanon, Oreg., 2008. ‘B-5.0815’has a wider flag leaf width than ‘Kenblue’ (Table 1). The inflorescencesof ‘B-5.0815’ produced in the field have panicle lengths of 12.2 cmcompared to the significantly shorter panicle of ‘Baron’ (8.9 cm). Thecombination of characters of earlier heading than Baron, long paniclelength not different from Kenblue, and a wider leaf blade than both‘Kenblue’ and ‘Baron’ distinguish ‘B-5.0815’. ‘B-5.0815’ has retainedthe unique characters during successive stages of propagation and hasshown to be a stable variety in asexual propagation.

‘B-5.0815’ has shown susceptibility to stripe rust (Puccinia striiformisWestend.) in tests near Lebanon, Oreg. ‘B-5.0815’ has shown similar drymatter yield in trials in Lexington, Ky. (Table 2) compared to ‘Kenblue’and ‘Ginger’ (US Plant Variety Protection 9100128) when tested in 2007and 2008. ‘B-5.0815’ is adapted North/South from the Kentucky borderthrough Canada, and East/West from Kentucky to Oregon. ‘B-5.0815’ issimilar to most Kentucky bluegrasses in performance with recovery fromplant stress from rhizomes. ‘B-5.0815’ is adapted from sandy to heavierloam soil textures and from slightly acid to slightly alkaline soil pH.

TABLE 1 Morphological characteristics of selected bluegrass cultivars,measured under field conditions in Lebanon, OR, 2008. Flag Flag HeadingDate of Panicle Leaf Leaf Date Flower Length Height Length Name (Julian)(Julian) (cm) (cm) (cm) ‘Kenblue’ 75 130 13.3 49.3 6.9 ‘Baron’ 124 1408.9 35.4 5.3 ‘B-5.0815’ 119 142 12.2 54.5 9.7 LSD, p = 0.05 2.36 2.581.62 7.83 1.95 Flag Leaf Sheath panicle Plant Width Length branch leafHeight Name (mm) (cm) number number (cm) ‘Kenblue’ 3.3 37.1 5.4 3.3 94.5‘Baron’ 5.3 38.6 5.0 3.7 62.0 ‘B-5.0815’ 6.9 36.9 4.9 3.7 80.7 LSD, p =0.05 1.03 ns ns ns 9.07

TABLE 2 Dry matter yields of Kentucky bluegrass varieties sown 6 Sep.2006 at Lexington, KY. Yield, Yield, tons/acre tons/acre 2-year Variety2007 2008 total ‘Kenblue’ 1.62 2.08 3.70 ‘Ginger’ 1.47 2.06 3.53‘B-5.0815’ 1.72 1.64 3.36 ‘Common’ 0.70 0.78 1.48 Lsd, p = 0.05 0.330.68 0.70

COMPLETE BOTANICAL DESCRIPTION OF THE VARIETY

-   Origin: ‘B-5.0815’ is a cultivar of a single vegetative clone of    Kentucky bluegrass discovered under cultivated conditions in a    planting of Kentucky bluegrasses planted near Lebanon, Oreg.-   Classification: Poa pratensis L.-   Growth habit: ‘B-5.0815’ is a perennial plant that spreads by    rhizomes, tillers, and apomictic caryopses. ‘B-5.0815’ produces a    large leafy plant with a highly fibrous root system. The    inflorescence of ‘B-5.0815’ is a panicle with some red purple 59A    (based on Royal Horticultural Society Colour Chart) coloring in the    panicle at 50% flowering.

Spikelet characters:

-   -   -   Spikelet length in lowest whorl.—3.2 mm.        -   Spikelet width in lowest whorl.—1.5 mm.        -   Floret number in lowest whorl.—2.        -   Upper floret length in lowest whorl.—2.7 mm.        -   Upper floret width in lowest whorl.—0.63 mm.        -   Lower floret length in lowest whorl.—2.9 mm.        -   Lower floret width in lowest whorl.—0.63 mm.        -   Outer glume length of spikelet in lowest whorl.—2.75 mm.        -   Inner glume length of spikelet in lowest whorl.—2.2 mm.        -   Spikelet length in third whorl.—4.35 mm.        -   Spikelet width in third whorl.—2.3 mm.        -   Floret number in third whorl.—2.3.        -   Upper floret length in third whorl.—3.0 mm.        -   Upper floret width in third whorl.—0.75 mm.        -   Lower floret length in third whorl.—3.4 mm.        -   Lower floret width in third whorl.—0.78 mm.        -   Outer glume length of spikelet in third whorl.—2.9 mm.        -   Inner glume length of spikelet in third whorl.—3.25 mm.        -   Floret color at early heading.—139C green with some            greyed-purple 187B.

-   Inflorescence characters:    -   -   Panicle length.—12.2 cm.        -   Flag leaf length.—9.7 cm.        -   Flag leaf width.—6.8 mm.        -   Branches per panicle.—4.9.        -   Panicle habit.—Upright.        -   Panicle type.—Open.

-   Mature plant height, including inflorescence: ‘B-5.0815’: 80.7 cm;    ‘Baron’: 62 cm. Color Notations, vegetative characters, based on The    R.H.S. Colour Chart (light quality, photoperiod, and general growth    of the plants affect color notations):

-   Leaf blade: folded in the bud, coarse compared to other Kentucky    bluegrasses.    -   -   Leaf blade color upper leaf surface.—‘B-5.0815’:137B green;            ‘Baron’: 137A green; ‘Kenblue’: 137A green.        -   Leaf blade color lower leaf surface.—‘B-5.0815’:137B green;            ‘Baron’: 137A green; ‘Kenblue’: 137A green.        -   Leaf blade texture rating.—‘B-5.0815’=coarse; ‘Baron’:            medium; ‘Kenblue’: fine.

-   Apomictic caryopses description: Caryopses (seed) weight of 1000    caryopses: 0.3320 g.    -   -   Caryopses weight class.—‘B-5.0815’=medium where            light=‘Sydsport’ (unpatented) and ‘Merton’ (unpatented) and            where heavy=‘Fylking’ (unpatented) or ‘Nugget’ (unpatented).        -   Width.—‘B-5.0815’=0.6 mm.        -   Length.—‘B-5.0815’=2.75 mm.        -   Keel shape.—Sharp.        -   Palea.—Strong hairs, teeth-like in character.        -   Overall shape.—Compressed.        -   Lemma.—Curls into seed, covering palea, papery in texture.        -   Hairs.—Present on lemma, on keel, and near rachilla,            somewhat similar to Poa trivialis.        -   Rachilla.—Conical tapered tubular shape, similar to a golf            tee.

1. A new and distinct variety of Kentucky bluegrass plant, substantially as described and illustrated herein, characterized particularly by a high dry matter forage yield and a coarse leaf texture. 